Method for operating a pump system

A method for operating a vacuum pump system comprising a plurality of pumps, the method comprising steps of:

• obtaining a target parameter to be optimized for the vacuum pump system as a whole;
• obtaining an operation target, wherein the operation target is provided by the plurality of pumps operating together with each pump in the plurality of pumps providing a respective operation parameter that contributes to the operation target and wherein the operation target is a flow level or pressure level required to be provided by the vacuum pump system when the vacuum pump system is operating;
• performing a first run of adjusting the operation parameters of the plurality of pumps to move the target parameter toward an optimum value for the target parameter while requiring that the operation target is met, wherein during the first run a fixed speed pump of the plurality of pumps is considered as a variable speed pump;
• determining that the first run of adjusting the operation parameters resulted in the fixed speed pump being assigned a speed that is greater than zero and less than a full speed of the fixed speed pump, and in response, performing a second run of adjusting the operation parameters of the plurality of pumps to move the target parameter toward the optimum value for the target parameter while requiring that the operation target is met so that the speed of the fixed speed pump is either zero or the full speed to provide adjusted operation parameters for the plurality of pumps, wherein a step size associated with adjusting the operation parameter of the fixed speed pump is larger for the second run than for the first run;
• and
• controlling the plurality of pumps to operate with the adjusted operation parameters.